1. Field of the Invention
The present invention relates to technology for controlling the storage of electronic files.
2. Description of the Related Art
For example, in today's information society, the number of files in storage is increasing on a daily basis, and this is a source of concern for people who utilize storage (for example, information processing system users and storage administrators). Among these files, there are numerous files that are not really necessary (for example, backups of old files, or files that have been copied and left as-is without much thought being given to them). Since deleting these unnecessary files increases free storage capacity, the technology disclosed in Japanese Patent Laid-open Publication No. 7-319897, for example, is known as technology for controlling the storage of electronic files. In this technology, for example, the degree of conformance of a first and a second file stored on a storage medium is acquired, and from this acquired degree of conformance a determination is made as to whether or not the first file and the second file are similar, and when, as a result, they are determined to be similar, one of them, either the first file or the second file, is deleted from the above-mentioned storage medium.
In the above-mentioned Japanese Patent Laid-open Publication No. 7-319897, when a first and a second file are determined to be similar, one of them, either the first file or the second file, is deleted. This saves storage capacity that would have been consumed. However, in Japanese Patent Laid-open Publication No. 7-319897, there is no particular criterion for determining which of the files, the first file or the second file, is saved. For this reason, there is no way of lowering the risk of the saved file being lost.
Further, in the above-mentioned Japanese Patent Laid-open Publication No. 7-319897, a determination of similarity is carried out by comparing all files using the brute force method. However, for example, when a large number of files are stored, since the scope of the search constitutes all of these numerous files, finding files that are similar to one another takes a long time.